in the lab, you are working with various compounds of phosphate. after undergoing a series of experimentations

Question

you determine that the formula weight for this phosphate compound is 150.82g/mol. under further test, you determine that the cation used in the formula has lost three electrons. determine the chemical formula for this compound.

Answer 1

Atomic weights: P=31 O=16 PO4 3- =95

Let the formula weight be 151 for ease of calculation.

151 - 95 = 56

Because PO4 is 3-, and because the metal "lost 3e-," the formula is MPO4 and not something like M3PO4 or M3(PO4)2. Therefore, looking for 56 on the periodic table, we come to M = Fe.

FePO4